Charge Transfer in DNA. From Mechanism to Application. Edited by Hans-Achim Wagenknecht (original) (raw)

Charge transfer and transport in DNA

Proceedings of the National Academy of Sciences, 1998

We explore charge migration in DNA, advancing two distinct mechanisms of charge separation in a donor (d)-bridge ({B j })-acceptor (a) system, where {B j } ‫؍‬ B 1 ,B 2 , . . . , B N are the N-specific adjacent bases of B-DNA: (i) two-center unistep superexchange induced charge transfer, d*{B j }a 3 d ؏ {B j }a ؎ , and (ii) multistep charge transport involves charge injection from d* (or d ؉ ) to {B j }, charge hopping within {B j }, and charge trapping by a. For offresonance coupling, mechanism i prevails with the charge separation rate and yield exhibiting an exponential dependence ؔ exp(؊␤R) on the d-a distance (R). Resonance coupling results in mechanism ii with the charge separation lifetime ؔ N and yield Y Ӎ (1 ؉ ␦ N ) ؊1 exhibiting a weak (algebraic) N and distance dependence. The power parameter is determined by charge hopping random walk. Energetic control of the charge migration mechanism is exerted by the energetics of the ion pair state d ؏ B 1 ؎ B 2 . . . B N a relative to the electronically excited donor doorway state d*B 1 B 2 . . . B N a. The realization of charge separation via superexchange or hopping is determined by the base sequence within the bridge.

On the Long-Range Charge Transfer in DNA

Journal of Physical Chemistry A, 2000

The sequence dependence of charge transport through stacked Watson-Crick base pairs was analyzed for coherent hole motion interrupted by a temporary charge localization on guanine bases. The relative rate of hole transfer to the GGG sequence has been expressed in terms of the frequency of jumps through adeninethymine base pairs separating adjacent guanine sites. The obtained expression yields practically the same sequence dependence as measurements, without invoking adjustable parameters. For alternating adeninethymine/guanine-cytosine sequences, our analysis predicts that the relative charge-transfer rate varies in inverse proportion to the sequence length at short distances, with change to the slow exponential decay at longer distances.

Direct Observation of the Hole Carriers in DNA Photoinduced Charge Transport

Journal of the American Chemical Society, 2016

The excited state behavior of DNA hairpins possessing a diphenylacetylenedicarboxamide (DPA) linker separated from a single guanine‒cytosine (G‒C) base pair by zero-to-six adenine‒thymine (A‒T) base pairs has been investigated by a combination of femtosecond and nanosecond transient absorption spectroscopy and femtosecond stimulated Raman spectroscopy. In the case of hairpins with zero or one A‒T base pair separating DPA and G, formation of both DPA anion radical (DPA-•) and G cation radical (G+•) are directly observed and characterized by their transient absorption and stimulated Raman spectra. For hairpins with two or more intervening A‒T base pairs, the transient absorption spectra of DPA-• and the adenine polaron (An+•) are observed. In addition to characterization of the hole carriers, the dynamics of each step in the charge separation and charge recombination process as well as the overall efficiency of charge separation have been determined, thus providing a complete account ...

DNA Charge Transport: from Chemical Principles to the Cell

Cell Chemical Biology, 2016

The DNA double helix has captured the imagination of many, bringing it to the forefront of biological research. DNA has unique features that extend our interest into areas of chemistry, physics, material science and engineering. Our laboratory has focused on studies of DNA charge transport (CT), wherein charges can efficiently travel long molecular distances through the DNA helix while maintaining an exquisite sensitivity to base pair π-stacking. Because DNA CT chemistry reports on the integrity of the DNA duplex, this property may be exploited to develop electrochemical devices to detect DNA lesions and DNA-binding proteins. Furthermore, studies now indicate that DNA CT may also be used in the cell by, for example, DNA repair proteins, as a cellular diagnostic, in order to scan the genome to localize efficiently to damage sites. In this review, we describe this evolution of DNA CT chemistry from the discovery of fundamental chemical principles to applications in diagnostic strategies and possible roles in biology.

Dynamics of Photoinduced Charge Transfer and Hole Transport in Synthetic DNA Hairpins

Accounts of Chemical Research, 2001

The dynamics of photoinduced charge separation and charge recombination processes in synthetic DNA hairpins have been investigated by means of femtosecond transient absorption spectroscopy. The driving force and distance dependence of chargetransfer processes involving singlet acceptors and nucleobase donors are consistent with a single-step superexchange mechanism in which the electronic coupling between the donor and acceptor is strongly distance dependent. The dynamics of reversible hole transport between a primary guanine donor and nearby GG or GGG sequences has also been determined and establishes that these sequences are very shallow hole traps. Frederick D. Lewis was born in Boston, MA. He received his B.A. degree from Amherst College in 1965 and his Ph.D. from the University of Rochester in 1968. Following a postdoctoral appointment at Columbia University with N. J. Turro, he joined the faculty of Northwestern University in 1969. He is currently serving as President of the Inter-American Photochemical Society. His research interests are focused on the relation between photochemical behavior and molecular structure in systems ranging from small molecules to DNA. Robert L. Letsinger was born in Bloomfield, IN. He received his B.S. degree in 1943 and his Ph.D. in 1945, both from MIT. He joined the faculty of Northwestern University in 1946 and is currently Clare Hamilton Hall Professor, Emeritus. He is best known for his pioneering studies in solid-phase synthesis and nucleic acid chemistry. His achievements have been recognized by election to the Nation Academy of Sciences and numerous awards, including the American Chemical Society A. C. Cope Scholar Award. His current interests include nanotechnology and its applications to DNA diagnostics. Michael R. Wasielewski was born in Chicago, IL. He received his B.S. degree in 1971 and his Ph.D. in 1975, both from the University of Chicago. Following postdoctoral studies with R. Breslow at Columbia, he joined the scientific staff of the Chemistry Division of the Argonne National Laboratory. In 1994 he joined the faculty of Northwestern University, where he is Professor of Chemistry. He held a joint appointment at Argonne until 1999, when all of his research activities moved to Northwestern. His research focuses on electron-transfer reactions, the synthesis of donor-acceptor molecules and materials, ultrafast photophysical and photochemical processes in organic molecules and optoelectronic materials, magnetic properties of radical ion pairs, and the primary events of photosynthesis.

Charge transfer in DNA and its diverse modelling approaches

Frontiers in Life Science, 2016

DNA nanostructures with molecular recognition qualities have been developed, but the conceptualization of DNA-based molecular nanoelectronics is still a thought-provoking subject. An efficient and speedy charge transfer (CT) process through DNA nanoassembly is demanded for farther exploitation of DNA nanoelectronics with programmable features. The CT properties are represented in terms of localization lengths. Because of the DNA molecule's unique and novel characteristics, it can be applied in a variety of multidisciplinary research areas such as nanobiomedicine, nanooptoelectronics and nanobiotechnology. By using this interesting phenomena, we can integrate nanotechnology with both, biology as well as engineering, and can use it as a tool for many biological and engineering applications such as DNA chips, DNA nanogrids and DNA nanoribbons. Here, we have presented a review on various experiments that measure CT and charge transport in DNA. It is a very wide and interesting area in which many scientists have published many articles. So here we have tried to show the whole picture of it.

Electronic Coupling for Charge Transfer and Transport in DNA

The Journal of Physical Chemistry B, 2000

We calculated electronic matrix elements for hole transfer between adjacent nucleobases in DNA. Calculations of the matrix elements for intrastrand and interstrand transfer were performed at the Hartree-Fock level employing the 6-31G* and 6-311G** basis sets. The matrix elements for intrastrand hole transfer, for which a wealth of experimental solution data is available, are almost independent of the basis set and exhibit an exponential interbase distance dependence, sensitivity to the donor-acceptor geometry, and dependence on 5′ f 3′ direction base sequence. The calculated intrastrand hole transfer matrix elements between adjacent thymines, v + (T,T) ) 0.16 eV, is in good agreement with the experimental estimate, v + (T,T) ) 0.18 eV, inferred from hole hopping in G + (T) m GGG (m ) 1-3). The features of the nucleobase bridge specificity for superexchange-induced hole hopping between guanines in G + XY...G (X,Y ) T or A) were elucidated, with the prediction of enhanced efficiency of thymine relative to adenine as mediator. Information on superexchangemediated intrastrand and direct interstrand hole hopping between guanine bases was also inferred. Our results for interstrand, adjacent G + G coupling predict the existence of zigzagging pathways for hole hopping, in line with experiment.

DNA-mediated electron transfer: Chemistry at a distance

Pure and Applied Chemistry, 1998

The DNA double helix, containing a n-stacked array of base pairs in its core, represents a unique a n d efficient medium for long-range charge transport. D N A assemblies have been constructed containing tethered metallointercalators, and these provide chemically well-defined systems through which to probe the D N A n-stack. Using both spectroscopy and chemical assays of reactivity, we find electron transfer reactions mediated by the D N A base pairs to occur over long molecular distances. The structure of D N A facilitates chemistry a t a distance. Importantly, these long-range reactions depend sensitively upon base pair stacking, and hence are modulated by a n d report on the characteristic stacking within the double helix.